As rotors for use in a motor, patent documents 1-4 disclose rotors having the so-called Lundell type structure. The rotor includes a rotor core having a plurality of hook-like magnetic poles in the circumferential direction and a field magnet coil wound within the rotor core, and electrical power is supplied to the field magnet coil to cause respective hook-like magnetic poles to function as the different magnetic poles alternatively.
In the rotor of patent document 1, an auxiliary magnet is arranged between poles, and a field magnet coil and magnetic flux are combined to enhance the output. Also, in the rotor of patent document 2, an auxiliary magnet is arranged between poles, and the magnetomotive force of the auxiliary magnet allows for the braking of a rotor that would continue to rotate due to inertial force. Further, in the rotor of patent document 3, a magnet that is shaped to eliminate leakage magnetic flux and enhance the output is arranged on a distal inner circumference of a hook-like magnetic pole.
Further, in the rotor of patent document 4, a hook-like magnetic pole projects outward in the radial direction from the peripheral part of a core base (a disk part in the document) and extends in the axial direction. An auxiliary magnet is arranged on the rear surface of the part (flange in the document) extending in the axial direction of the hook-like magnetic pole. A portion at the abutting side (outward in the radial direction) is magnetized to the same polarity as the corresponding hook-like magnetic pole. This allows for the reduction of leakage magnetic flux that would occur at the hook-like magnetic pole.